Researchers said Tuesday they believe there is virtually no risk of contracting the AIDS virus from an infected doctor or dentist who follows standard infection-control practices.

Studies were conducted on some 2,500 patients who had undergone invasive surgical procedures between 1978 and 1991 by three HIV-infected doctors: a New Hampshire surgeon, a Baltimore surgeon and a Florida dentist.

In one study, 413 patients of an infected Baltimore breast surgeon's patients were tested and only one was identified as HIV-infected. Through genetic testing, scientists concluded that this patient probably got the virus from an unrelated blood transfusion.